This research is an initial step towards developing a sequential multi- model approach to the supplemental stimulation of premature infants. This study will compare the effects of vestibular (oscillating waterbed) and tactile/kinesthetic (massage & limb flexion/extension) stimulation on: 1. state regulation during treatment; 2. non-treatment state regulation; 3. neurobehavioral maturation. Low birth weight (LBW) and very low birth weight (VLBW) preterms will receive either a course of fast vestibular [FVS: 25-30 oscillations per min. for i hr. prior to each daytime feeding for 3 wks (N=10 LBW, 10 VLBW Ss)], slow vestibular [SVS: approx. 16 oscillations per min. (same freq. & duration as FVS) (N= 10 LBW, 10 VLBW Ss)], or tactile/kinesthetic [T/K: 3 daily 15 min. sessions for 3 wks. (N= 10 LBW Ss, 10 VLBW Ss)] stimulation. Specific goals include: 1. confirming if FVS promotes more frequent and deeper sleep states; 2. confirming if SVS increases periods of quiet alertness and visual pursuit; 3. confirming that T/K promotes arousal and motor output. Prior to, during, and following treatment, state regulation and behavior will be examined through videotaped observations. Neurobehavioral maturation will be assessed pre- and post-treatment with an adaptation of the Brazelton (i.e. BNBAS). Post-treatment findings from stimulated preterms will be compared against control preterms (N= 20) and full-term neonates (N =10).